The present invention generally relates to medical devices. Specifically, the invention relates to an interface device implemented to telemetrically and wirelessly transmit physiologic and cardiac data obtained from one or more implantable medical devices (IMDs). More specifically, the invention relates to an information remote monitor (IRM) medical device, having data communications with the IMDs and a remote computer/server that is accessible by Medtronic, Inc. and other care providers to seamlessly and continuously transfer data and enable remote monitoring and management of patients with chronic disease. Preferably, the IRM is placed in the patient""s home/room to access the IMD and transmit stored data via various data transmission schemes to a remote server or other expert centers.
The present invention relates generally to telemetry systems for uplink and downlink telemetry transmission between at least one implantable medical device and an IRM. The IRM is implemented to overcome the problems encountered in providing patient services that are generally limited to in-hospital operations.
Prior art methods of reviewing patient data and conducting clinical follow-ups on patients with one or more IMDs, requires a patient to go to a clinic or hospital. Further, if the medical condition of a patient with an IMD warrants a continuous monitoring or adjustment of the device, the patient would have to stay in a hospital indefinitely. Such a continued treatment plan poses both economic and social problems. Under the exemplary scenario, as a segment of the population with IMDs increases, many more hospitals/clinics, inlcuding service personnel will be needed to provide in-hospital service for the patients, thus escalating the cost of health care. Additionally, the patients would be unduly restricted and inconvenienced by the need to either stay in the hospital or make very frequent visits to a clinic.
Yet another condition of the prior art practice requires that a patient visit a clinic center for occasional retrieval of data from the IMD to assess the operation of the device and gather patient history for both clinical and research purposes. Further, if a patient with IMDs is taking a drug, it is often clinically prudent to monitor the dose and its impact on the performance of the IMD. Furthermore, the IMD may be adapted to monitor the patient""s drug intake, compliance and effectiveness by directly measuring the dose of the drug in the patient. Normally, such data is acquired by having the patient in a hospital/clinic to download the stored data from the IMD or by direct examination, such as, for example, a blood test. Depending on the frequency of data collection, this procedure of assessing a chronic condition of a patient with IMDs may pose serious difficulty and inconvenience for patients who live in rural areas or have limited mobility.
Current practice in the art involves the use of an external programming unit for non-invasive communication with IMDs via uplink and downlink communication channels associated with the programmers. In accordance with conventional medical device programming systems, a programming head is used for facilitating two-way communication between IMDs and the programmer. In many known implanted IMD systems, a programming head is positioned on the patients body over the IMD side such that one or more antennae within the head can send RF signals to, and receive RF signals from, an antenna disposed within the hermetic enclosure of the IMD or disposed within the connector block of the IMD in accordance with common practice in the art. As was indicated hereinabove, procedures that require downlink and uplink using programmers require that the patient be present at the hospital or clinic. A programmer of this type is described in more detail in U.S. Pat. No. 5,345,362 issued to Thomas J. Winkler, entitled PORTABLE COMPUTER APPARATUS WITH ARTICULATING DISPLAY PANEL, which patent is hereby incorporated herein by reference in its entirety.
In the context of the present invention, programmers are complicated and expensive units to deploy in patients"" homes to implement a highly distributive chronic patient monitoring and management. Notwithstanding, more recently, it has been proposed to provide communication systems for IMDs in which the programming head is eliminated and communication occurs directly between the IMDs and the programmer located some distance from the patient. Such programmers still require the patient to be within telemetry range and therefore are not compatible with a remote patient management. Such systems are disclosed in U.S. Pat. No. 5,404,877 to Nolan et al, and U.S. Pat. No. 5,113,869 to Nappholz. In the Nappholz patent, in particular, broadcasting RF signals from an IMD to a programmer that may be located some feet away from the patient, is suggested. Such a communication system is also disclosed in U.S. patent application Ser. No. 09/303,178 for A TELEMETRY SYSTEM FOR IMPLANTABLE MEDICAL DEVICES, filed Apr. 30, 1999 by Villaseca et al, which application is incorporated herein by reference in its entirety.
In the context of remote communication relating to IMD data transfer and exchange, for example, U.S. Pat. No. 3,769,965 issued to Raddi et al, discloses a monitor apparatus for implanted pulse generator. Specifically, a monitor apparatus is disclosed for monitoring electrical stimulation signals due to either natural or artificial electrical stimulation of a body part via a communication link such that the repetition rate of the electrical stimulation signals can be determined. The monitor apparatus comprises the subsystems: a transducer; a communication link or network; and a receiver. The transducer is adapted to sense the electrical stimulation signals generated either naturally or by an electronic organ stimulator, such as an implanted cardiac pacer, and to convert the electrical stimulation signals to audible signals such as tone bursts. These audible tone bursts are then transmitted over a communication link such as the standard telephone network to the receiver located at a remote telephone station, typically a cardiologist""s office. The receiver is adapted to measure the time interval between received tone bursts. The receiver is further adapted to display or indicate to an observer the time interval between received tone burst. If desired, the receiver can be adapted to indicate directly the repetition rate of the stimulation signals. The information is then utilized by an observer for diagnostic purposes. The monitor apparatus also includes a test means for testing the integrity of the apparatus including the transducer, the communication link and the receiver.
Further, U.S. Pat. No. 3,885,552 issued to Kennedy discloses a diagnostic method and system for the detection and transmission of data from a remote location to a central location.
U.S. Pat. No. 4,142,533 issued to Brownlee et al, discloses a monitoring system for cardiac pacers. It discloses a complete system for telemetering and monitoring the functioning of an implanted pacemaker as well as controlling the testing of the functions from a remotely located central facility is disclosed specifically comprising the provision of capabilities for directly and simultaneously transmitting from the pacer, electrical signals indicative of multiple pacer functions, such as, pacer rate, cell voltage, refractory period, heart rate with pacer inhibited, R-wave level and sensing margin, sensing circuit and other component failure, cardiac electrode lead break, and hermetic integrity. The indicative signals are picked up at the patient""s location for local analysis and/or telephonically communicated to a remote central monitoring station. The central station may control testing of the pacemaker functions by transmitting command signals back telephonically for coupling through cooperating external and implanted inductances or magnetically controlled switches to the implanted pacer circuitry. U.S. Pat. No. 5,467,773 issued to Bergelson et al, discloses cardiac pacing remote monitoring system. Remote monitoring of cardiac electrical activity and/or pacemaker function under extensive control by personnel at a central station over the operation of a monitoring instrument at the patient""s home, to thereby reduce reliance on active participation by the patient and to enhance useful information and suppress undesirable information in the signals transmitted between the home monitoring unit and the central station. U.S. Pat. No. 5,626,630 to Markowitz et al, discloses a medical telemetry system using an implanted passive transponder. The telemetry system includes a remote monitoring station, a repeater worn externally by a patient and a quasipassive transponder attached to a device implanted in the patient. The remote monitoring station communicates to the repeater to initiate an interrogation routine between the repeater and the transponder to extract patient condition information from the implanted device. When the repeater receives the condition information, it relays it to the remote monitoring station. The transponder is specially designed to operate with an extremely low level of power, less than 1 nW/baud, and to be compatible for attachment to existing implanted devices. The transponder can operate at a very high data rate, including a rate of about 100 kbps. U.S. Pat. No. 5,720,770 to Nappholz et al, discloses a cardiac stimulation system with enhanced communication and control capability. Specifically, a cardiac stimulation system is provided which delivers long term cardiac therapy without a personal supervision by a physician. The system includes a cardiac stimulation device implanted in a patient and an external device in constant or periodic communication with the cardiac device. The external device is used to control the pacemaker operation. The external device receives updates of the condition of the patient and the operation of the cardiac device and the therapy provided by the cardiac device. This information is transmitted by the external device over a standard telephone network which may consist of hardwired network, a cellular network, or a combination thereof to a remote control device operating near the physician and/or a monitoring station used for monitoring and data logging information from a plurality of patients. The cardiac device, through the external device can also communicate directly and exchange information with the patient over an RF channel. Finally, the external device may be provided with ground position indication system for locating the patient geographically in an emergency. U.S. Pat. No. 5,944,659 to Flach et al, relates to architecture for TDMA medical telemetry system. A medical telemetry system is provided for collecting the real-time physiologic data of patients (including ambulatory patients) of a medical facility, and for transferring the data via RF to a real-time data distribution network for monitoring and display. The system includes battery-powered remote telemeters which attach to respective patients, and which collect and transmit (in data packets) the physiologic data of the patients. The remote telemeters communicate bi-directionally with a number of ceiling-mounted RF transceivers, referred to as xe2x80x9cVCELLs,xe2x80x9d using a wireless TDMA protocol. The VCELLs, which are hardwire-connected to a LAN, forward the data packets received from the telemeters to patient monitoring stations on the LAN. The VCELLs are distributed throughout the medical facility such that different VCELLs provide coverage for different patient areas. As part of the wireless TDMA protocol, the remote telemeters continuously assess the quality of the RF links offered by different nearby VCELLs (by scanning the frequencies on which different VCELLs operate), and connect to those VCELLs which offer the best link conditions. To provide a high degree of protection against multi-path interference, each remote telemeter maintains connections with two different VCELLs at-a-time, and transmits all data packets (on different frequencies and during different timeslots) to both VCELLs; the system thereby provides space, time and frequency diversity on wireless data packet transfers from the telemeters. The telemeters and VCELLs also implement a patient location protocol for enabling the monitoring of the locations of individual patients. The architecture can accommodate a large number of patients (e.g., 500 or more) while operating within the transmission power limits of the VHF medical telemetry band. U.S. Pat. No. 6,073,046 issued to Pattel et al, discloses a heart monitor system to enable a medical facility, after discharge of a cardiovascular patient, to remain in contact with the patient. The patient is provided with a multiple lead EKG terminal spread placed on the body, and the signals therefrom are collected and transmitted. They are transmitted to a remote central location. At the central location, the transmitted EKG data is analyzed. It is compared with normal EKG signals and signals captured in time from the same patient as part of the patient history. The evaluation is done through a neural network which forms an output signal automatically or through intervention of a cardiologist sending an alarm condition signal to the patient instructing the patient to get immediate treatment at the patient""s location or to otherwise go to a specific medical facility. Signal preparation includes providing EKG signals through a multiplexer, conversation into a digital data, removal of bias signals, stabilization of this EKG base line, compression and data transmission through a modulator. The receive signal is reconstructed to provide an EKG signal of the patient which is then evaluated in the neural network. As appropriate, transmitter/receiver repeater stations and synchronous satellites are used to convey these signals. U.S. Pat. No. 6,162,180 issued to Miesel et al discloses a non-invasive cardiac monitoring system and method with communications interface. Specifically, a system and method for determining a patient""s cardiac output in a non-invasive manner and transmitting cardiac output data to a remote host processor, a communications system, or a local output device is disclosed. A noninvasive cardiac monitoring approach utilizes an implantable medical device coupled to an oxygen sensor. The oxygen sensor provides venous oxygen saturation data to the implantable medical device. An oxygen consumption unit produces oxygen consumption data using air exhaled by a patient. A processing unit calculates a cardiac output result in real-time using the venous oxygen saturation data, the oxygen consumption data, and arterial oxygen saturation data assumed to be about 100% or acquired using a sensor external to the patient. The implantable medical device may transmit the venous oxygen saturation data to the processing unit using electromagnetic signals or acoustic signals. The implantable medical device may be a pacemaker, a pacemaker, cardioverter, defibrillator (PCD), an oxygen sensing device, or an implantable hemodynamic monitor. The processing unit may store the cardiac output data/result for a period of time and/or communicate the
cardiac output result to the remote host processor substantially in real-time via a communications interface. The interface may include a modem, a computer interface, a network interface, or a communications system interface, for example. The processing unit may communicate the cardiac output result to the remote host processor in an analog, digital or optical form.
Use of the systems of the prior art may not be conducive for patients to stay in their home while receiving a high quality continuous monitoring and clinical service. In sharp contrast, the IRM of the present invention is intended to provide means for a patient to transmit data from their residence to a health care provider and/or remote server. As will be discussed in the preferred embodiments herein, the design is focused on making the process very easy and automated for the patient. The complete system of the IRM in conjunction with a server, a web browser and a remote communication system, allows the patient to stay in their home, thus reducing patient visits to the physician or the hospital, while increasing the level of care at a reduced cost.
The present invention relates to a communications system between one or more implanted devices (IMDs) in a patient and an associated information remote monitor (IRM) located at a distance from the IMDs to enable the transmission of physiologic and cardiac data from at least one of the IMDs.
In a preferred embodiment the IRM includes software adapted to communicate with Chronicle(copyright) which is an implantable hemodynamic monitor. The Chronicle(copyright) without limitation, stores trend data in a large buffer in RAM with resolution ranges from a few seconds to several minutes, depending on storage time interval.
The IRM is implemented to collect patient/medical device data in a patient""s home for transmission to a remote server or clinician to enable remote and chronic patient monitoring and management. In the preferred embodiment the IRM is adapted to download data from an external pressure reference (EPR) simultaneous with downloading data from the Chronicle(copyright) using a wireless telemetry data transfer.
The IRM is adapted for connection to a PC to use the PC for data transfer. In the alternate, the PC may be used to control the IRM and program the implanted device thereby implementing the IRM as a programmer. In the context of the present invention, the IRM could transfer EPR and Chronicle(copyright) (IMD) data through the PC to a server or a remote clinical/physician center. The IRM may also, via a modem and other wireless communications media, transfer the data to a server or the remote center. In one embodiment, the IRM utilizes an integral modem to dial a server and transfer data via FTP, PPP and TC/PIP protocols.
The IRM includes various structures to promote ease of use in the home environment. Specifically, ergonomic structures in combination with user interface instructions, displays and audible communication make the IRM a user friendly device for application in the home environment.